In the manufacturing method of integrated circuits (ICs) in the past, the traditional process is electroplating and etching. Since the accompanied lithography requires complex and precise stacking of the conductive pattern to form a circuit, the costs and time consumed is high. Alternately, printing a conductive metal film directly on the substrate, and sinter heating to form a circuit pattern is a simple and low-cost manner. It therefore has potential for development.
Silver ink is often used in the inkjet printing process. In the prior art, a conductive silver is formed by reduction by heating at a high temperature, and is applied on the rigid silicon substrate. The silicon substrate has the disadvantage of inflexibility. However, when applied to the flexible substrate, the heat resistance of the flexible substrate is considered due to the temperature of the subsequent sintering to form the heating circuit. For example, the heat resistance of the polyimide (PI) substrate is between 250° C. and 300° C. according to the degree of polymerization.
In “Polyhedron 2002, 21, 1289-1297 and J. Mater Chem, 1999, 9, 1771-1780”, it is proposed to use silver single-sided bonding 2,2,6,6-tetramethyl-3,5-heptanedionato (TMHD) or a complex having a similar structure, for example, 1,1,1,5,5,5-Hexafluoroacetylacetone (HFAC). Such complexes can be used in chemical vapor deposition, which means that they have the characteristics of low-temperature pyrolysis. However, because HFAC contains functional groups of halogen fluoride, it is a toxic pollutant and not suitable for use under current environmental requirements. Further, the disadvantage in the prior art is the silver complex having large functional groups on the other end, thus making it difficult to cleave to measure the resistance or to have poor resistance.
Therefore, there is a need to provide a silver compound capable of cleavage at a low temperature to form a silver film having an excellent conductivity to solve the problems existing in conventional technologies, as described above.